Sparking plug.



I Z. TUCKER 81 L. W. MARKWURT.

SPARKING PLUG.

APPLICATION FILED MAY K8. 1914.

1,205,289, Patented Nov. 21, 1916 UNITED STATES PAT-Eur .1 OFFICE.

JAMES Z. TUCKER AND LOUIRE; W. MABKWORT, OF ST. LOUIS, MISSOURI.

, Breanne PLUG.

To all whom it may concern: v t

Be it known that we, JAnias' Z. TUCKER and LOUIS W. MARKwon'r, citizens of the United States of America, and residents of the city of St. Louis and State of Missouri,

. means in-a spark plug whereby the sparking gaps between the electrodes cannot become disarranged on account of one electrode becoming concentrically moved from another electrode.

A still furtherobject is to construct a spark plug with a series of electrodes in out in the appended claim, reference being had tothe accompanying drawings exemplifying the invention, and in which,

, Figure 1 is a vertical section taken through a spark plug, said plug being se cnred to a portion of an engine cylinder.

ig. 2 is an inverted View of Fig. 1 showingthe sparking end of the spark plug.

eferring by numerals to the accompanying drawings: 1 designates a portion of an engine cylinder, said cylinder having an inverted opening 2 in which is mounted a sparking plug 3. This-spark plug comprises a cylinder engaging portion 4 having an exteriorly threaded portion 5 and an interiorly threaded portion 6. Formed in the portion 4 of the spark plug is a shoulder 7. Mounted in said portion 4 is an insulated core 8,

' s'ai core Having I an enlarged portion 9 formed thereon. Formed on the lower end of'said enlarged portion is a shoulder 10,

said shoulder? adapted to rest on a packing nwashe'i' 11 which is mounted on the shoulder o-f-the cylinder engaging portion 4.

i Engaged in the interiorly threaded portion 6 of the portion 4 is a threaded bushing I2,,said bushing adapted to have its lower Specification of Letters Patent.

Application flledzllay 18, 1914. Serial No. 839,197.

end engage the upper shoulder 13 which is formed on the enlarged portion 9' of the insulated core ,8. Formed in the core 8 is a centrally arranged opening 14, said core, at its lower end, terminatingjn a chamber 15. Mounted in said opening 14 is the'main or first electrode 16. electrode 16 has a depending portion 17 se cured thereto, the lower end of said depending portion 17 being bent at right angles forming a sparking point 18. Carried by the electrode 16 is a collar 19 which is adapted to engage against a shoulder 20 formed at the upper end of the chamber 15. Mounted on the upper end of the electrode 16, and on the upper end of the core 8, is a cap 21, said electrode being held in position by the thumb nut 22 engaging against said cap.

Secured to the lower end of the core 8 are a pair of depending points 23, the lower end of said'points being. secured to the circular shaped portion 24, said portion 24 en-' circling the depending portion 17 of the electrode 16. These points 23 and circular shaped portion '24 provide an intensifier or second electrode.

Secured to the lower end of-the cylinder engaging portion a is a ground or third electrode 25, said electrode having an extending portion 26.

In the operation of this improved spark plug, one end 27 of the ignition circuit Wires is held in contact with the first electrode 16 by the thumb nut 22 while the other end 28 of said ignition circuit is grounded at'29. \Vhen the ignition circuit is closed, the current, taking the path of least resistance, will travel the first electrode 16 and jump and-spark at the gap 30 to the second electrode, and than will jump and spark at the gap 31 to the third electrode, thereby giving two sparks.

In the mounting of spark plugs on in-. ternal combustion engines, it quite, frequently happens that the points of the electrodes get separated to such an extent that inferior sparks are made, and sometimes, none at all. In thisimproved construction, one of-the electrodes, comprising a circular shaped portion, will prevent the aforesaid ailment on account of its position in relation to the other electrodes on account of the concentric relation that the first and tending portion 26 of the third electrode 25 The lower end of said I 

